Dangerous Definitions

Kill vehicles approaching a cloud of decoys, one of which contains a warhead.

From a technical perspective, the Obama administration’s approach to missile defense has been particularly disappointing – and is potentially dangerous. Originally the administration said it would require missile defenses to be “proven,” implying that these systems would finally be subjected to rigorous and realistic testing, which was absent during the Bush administration. We have long advocated such testing.

So it was surprising when (a) the administration’s Ballistic Missile Defense (BMD) Review stated that “The United States is currently protected against limited ICBM attacks,” and (b) the President called the Aegis missile defense system “proven” in the announcement of his proposed European system in September 2009.

Neither of these statements are true in any meaningful sense. Neither the Aegis system nor the Ground-Based Midcourse Defense (GMD) system fielded in Alaska and California has been subjected to realistic tests against the kind of attacks and under the conditions you would expect in the real-world. Neither system is “proven” in the usual sense of that term.

The technical people at OSTP and the Pentagon clearly understand these issues, so what’s going on here?

The Pentagon is using sleight of hand: it is defining the “threat” very narrowly – as something the defense may be able to defend against – and then exaggerating the system’s ability to deal with that threat.

Consider the BMD Review statement that the United States is “currently protected against limited ICBM attacks.” For the United States to be “protected” against missile attacks, the missile defense would have to be able to stop missiles fired at the U.S. and be able to do so reliably. As we discuss below, there’s no evidence it can do either against a real-world attack.

The Pentagon has defined a “limited missile attack” as an attack by a limited number of missiles, and by missiles that have no countermeasures, or very simple countermeasures that the defense knows about in detail in advance.

So it argues that if the anti-missile system can see an object and maneuver to hit it – which is what the tests of the GMD and Aegis systems have so far been about – then it might be able to hit a missile attacking the U.S. if that missile carries no countermeasures.

But it makes no sense to assume that North Korea, Iran, or any other country would spend years developing a long-range missile to hit the U.S. – and have the technical expertise to do so – and not have some of its aerospace engineers also design countermeasures that would make the missiles effective against defenses it knows the U.S. has been building. Countermeasures would not be an afterthought.

As both the U.S. intelligence community and our Countermeasures report found, effective decoys and other countermeasures can be built with less sophisticated technology than is needed for a long-range missile and nuclear warhead. The 1999 National Intelligence Estimate by the U.S. National Intelligence Council stated:

We assess that countries developing ballistic missiles would also develop various responses to US theater and national defenses… Many countries, such as North Korea, Iran, and Iraq probably would initially rely on readily available technologies… These countries could develop countermeasures based on these technologies by the time they flight test their missiles.

What about reliability? The test record of the GMD system is not good enough to claim the defense is reliable, even against missiles without countermeasures. The system has had few intercept tests under a very limited set of conditions. And even in that case the test record has not been great. The Pentagon has only conducted six intercept tests of the GMD system since the decision to field the system was made in December 2002, and half of those have failed. So even with a creative definition of “limited attacks” the statement that the U.S. is “currently protected” is not true.

What about the statement that the Aegis missile defense system is “proven”? The current Aegis interceptor (SM-3 Block 1A), is intended to intercept missiles up to about 1,500 km range. The Pentagon considers the Aegis anti-missile system “proven” – even though it has not been tested against missiles with countermeasures – because it defines the threat Aegis may face to be missiles without countermeasures. The argument seems to be that the most likely threat from Iran is an attack by potentially large numbers of conventionally armed missiles, to which Iran would not bother to add countermeasures, even if it could make them.

This argument is questionable for various reasons. Even if this is the threat, the statement that Aegis is “proven” is not true in any meaningful sense. As with the GMD tests, the Aegis tests have been done under a limited set of controlled conditions, and to argue that this means the system is “proven” against attacks under other conditions is wishful thinking, and should not be the basis of military planning.

Why are these creative definitions potentially dangerous?

First, if military and political leaders believe they have defensive capabilities that they do not in fact have, that can lead them to make bad decisions. For example, if leaders believe they have effective anti-missile systems it may encourage them to take aggressive actions that are in fact likely to make another country launch missiles at them. If the defense can’t actually stop that attack, the result can be disastrous.

It’s worth noting that the claim that Aegis is “proven” has led officials to believe the U.S. should buy and deploy many hundreds of Aegis interceptors before they have actually been shown to be effective. This is not sound military or economic policy.

Second, these ambiguous and exaggerated claims also lead people to believe that Aegis would work against attacks other than short-range missiles with no countermeasures. In particular, if people don’t understand the nuance with which the Pentagon is using the word “proven” then they may assume the system could also stop nuclear missiles equipped with countermeasures, which not even the Pentagon is claiming.

In addition, inflated claims about the current Aegis interceptor tends to lead political and military leaders to have an ungrounded optimism about the capability of future Aegis interceptors intended to engage longer range missiles. These future interceptors, as noted above, will certainly need to deal with countermeasures and there is no evidence they will be able to.

In the meantime, however, enthusiasm for these future systems is complicating current discussions about ratifying the New START treaty.

It would be ironic if the administration’s real steps to reduce nuclear threats to the United States were derailed – both domestically and internationally – by its pursuit of a system with known shortcomings that has yet to undergo realistic testing.

The technical reality is that countermeasures remain the Achilles Heel of missile defenses. No amount of word play and wishful thinking can change that technical fact.

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David Wright, physicist and co-director of the UCS Global Security Program, is an established expert on the technical aspects of arms control, particularly those related to missile defense systems, missile proliferation, and space weapons.